Combined electric plug and switch.



D. M. EDWARDS. COMBINED EvLEcmc PLUG AND SWITCH. A

APPLICATION FILED SEPT.27'. 19|?.

Patented Apr. 9,1919.

1M .w 9% N New U ww 99.. 9 N m. S. m .W ma W N wv Q. KN NN QN W Q 'wie1% DAVID EDWARDS, OF LONDON, ENGLAND.

COMBINED ELECTRIC PLUG SWITCH.

To all whom may concern Be it known that I, DAVID MUSGRAVE ED- -wARD's,a subjectl of the King of'Great Britain, residing in London, England,have invented a certain new and useful Combined Electric Plug andSwitch, of which the following is a speciiication.

The invention relates to a .combination of an electric switch with awall socket and l)nhe invention differs. from other previously knowndevices for this ur vose in being ada tedy for easy application toswitches o usual construction and mount- 'in'g and for this urpose thewall socket and plug are fitted y the side of and adapted to be placedon the same support as the switch.

According to the invention a wing, or projection, on the plug engages,when the plug is inserted in the socket, wlth a plunger operating theswitch and displaces 1t against the resistance of a The device accor gto the invention 1s ver easily adapted to the conditions in which theplug and switch, o r the switch only, are to be made water-tight, but-1t1s also very useful, wherever circuits conveying currents are closed oro ened by wall plug contacts, for example, or electric heating a paratusand for machine tools 1n worksliops.

In the accompanying drawings, Figures 1 and- 2 are, respectively, asectional elevation and a plan of an example of a combined wall socketplug and switch according to the invention in which the combination 1smade water-tight. Fig. 3 shows the plug removed and replaced by a cap. Flgs. 4 and 5 show modifications in which the. parts are not inclosed ina water-tight casng.

In the example shown in' igs. 1-3, 1s a plug contact device of u sualconstruction, but provided on one side with a wing pro] ection 2 adaptedto enga e with a plunger 3 sliding in a tubular gui e 4 bolted byflanges 5 to the cover 6 of a metal casing 7, in which is inclosed atumbler switch 8 of usual type.

Specification of Letters Patent.

Patented Apr. 8, 1919.

Application led September 27, 1917. Serial No. 193,570.

Contact pins 9 and 10 of the plug 1 engage in well-known manner withtubular contacts in a porcelain socketll. The socket 11 is inserted in ashort metal tube 12 screwthreaded externally and secured to the cover ofthe casing 7 by a ange 13. A circular nut 14 engaging with the thread ofthe tube .12 and provided with a milled head serves to compress arubberpacking ring 15 to prevent any access of water to the socket. f the lit.of the plunger 3 in the tube 4 is not' suiicient to prevent waterfinding its way to the switch contacts a packed gland may be provided. Arecess 16 in the plunger 3 engages with the pip 17 of the tumbler switch8 and the arrangement is such that as the plug. 1' is inserted in itssocket, the plunger is displaced by the wing 2 against .the resistance'of a spring 18 to close the switch contacts 19, which are ,onlycompleted when the plug contacts have been pushed home. f

On the withdrawal of the plug, the plunger 3 is rapidly forced back by'the spring 18 and by the action of the switch springs the contacts 19are released before the plug contacts have been withdrawn, so that nosparking at the plug contacts or shocks ,to the operator are possibleeither on the insertion or the withdrawal of the plug.

Fig. 1 shows in full lines the position of theplunger when the plug isinserted and the tumbler switch is closed; the positions of'theplungerand of the wing projection of the plug just before the insertion of thelatter are shown by the dotted lines.

The helical spring 18 can be replaced by lanother suitable form, forexample, by a plug of rubber or other elastic material.

As shown in Fig. 3, when the plug 1 is not in use, the socket can beclosed by a metal cap 20 provided with an internal screw thread engagingwith the thread on the tube 12.

The modifications shown in Figs. 4 and 5 are suitable for conditionswhich do not require that the parts should be wateretight. Similar partsare denotedby the same references as in the preceding figures.

In the device shown in Fig. 4, a spring 18 may be inserted in the tube 4as shown in 1, but this spring may be omitted if the arrangements aresuch, as shown by the dotted lines, that the full travel of the plungeris completed before the tumbler switch has reached the dead point; inthis position the tumbler contacts are engagement,.. but there is a,torsional stress giving.

a quick release as soon as the plug is removed. i v In Fig. 5 the solidplunger is replaced by a piston 22, to which is attached a rod 23,enlarged at one part into a ring to receive the pip 17 of the tumbler.The rod 23 is shown supported by a guide 24. e

The invention is not limited to the tum bler type of switch, but isapplicable to any type of tumbler switch havinga proJecting handle. A

Having thus describedv the nature of the said invention and the bestmeans I know of carrying the saine into practical edect, I claim 1'. Incombination, an electric switch, a casing for the switch, a handleoperating the switc contacts and projecting throu h the said casing, awall socket, a plug a apted to engage. in the said socket, a linearlysliding member engaging said handle, and a win on said Yplug adapted onthe insertion of the plug in the socket to move said sliding member toclose the switch contacts.

2. In. combination, an electric switch, a4

casing for the switch, a handle operating the switch contacts andprojecting through the said casing, a wall socket, a plug adapted toengage in the said socket, .a-linearly sliding member engaging said4handle, a wing` on4 j said plug adapted on'the-insertion of the lug inthe soc et to move said sliding mem- Eer to close the switch contacts,and a spring adapted to move said slidingmember in the oppositedirection when said plug is withdrawn from the socket.

3. In combination, an electric switch, a casing for the switch, a handleoperating the switch contacts and vprojecting through the said casing, awall socket, a plug adapted to engage in the said socket, a tubularcasing, a plun er slidable in said casing, and means associated withsaid plunger and engaging saidhandle to close the switch contactswhensaid plug is inserted in. said socket.

4. In combination, an electric switch, a casing for the switch, ahandleoperating the switch contacts and projecting through the said casing, 'awall socket, a plug' adapted to engage in the said socket, a tubularcasing, a

ciated with saidplunger and'engaging said handle to close the switchcontacts 'when said plug 'is -inserted in said socket, and a spring insaid tubular casing to move the 'plunger and thereby operate thehandleto open 4the said contacts.

5. In combination, an receptacle for the switch, a -cover for the topofthe receptacle having an opening, a`

handle operating the switch and projecting through said opening, asocket on the said cover, -a plugbadapted to 4be inserted in saidsocket, a tu plunger slidable in said tubular casing and engaging withsaid handle, and means associated with the plug adapted to 'move saidplunger and close said switch whenl the plug is inserted in the socket.

6. In combination, an electric switch, a receptacle for the switch, acover for the top of the receptacle having an opening, a handleoperating the switch and projecting through said. oening, a socket onthe said cover, a plug a apted to be inserted in said socket,V a tubularcasing on the cover, a plunger 'slidably mounted in said tubular casingand engaging with said handle, 'and a wing on said plug to engage andmove said plunger to close said switch when the plug is inserted in thesocket.

7. In combination, an electric switch, a receptacle for the switch, acover for the top of the receptacle having an opening, a handleoperating the switc .projecting through said opening, a socket on 'thesaid cover, a plug adapted to be inserted in said socket, a tubularcasin on the cover, a plunger slidably rnounte in said tubular vcasingand engagin lwith said handle, a wing on said plug a apted to engage andmove said plunger and close said switch whenl the plug is -inserted inthe socket, and a spring in said tubular casing adapted to open theswitch when the plug is w1thdrawn from the socket.

In testimony whereof I have signed my name to this specilication in thepresence of two subscribing witnesses.

l D. M. EDWARDS.

Witnesses:

C. S. HOPKINS, W. S. Mmmm.

electric switch, a l

ular casing on the cover, a-

